Gaidon et al. [1]}, [2]} introduced the problem of temporally localizing the actions in untrimmed videos, focusing on limited actions such as “drinking and smoking” [3]} and “open door and sitdown” [4]}. Later, researchers worked on building the following datasets that include large number of untrimmed videos with multiple action categories and complex background information. Some of these datasets target activities of high-level semantics (such as sports) while others include fine-grained activities (such as cooking). The details are summarized in Table REF .
